Mechanical movement for converting rotary into reciprocatory motion



March 15, 1949. R. J. COCHRAN MECHANICAL MOVEMENT FOR CONVERTING ROTARY INTO RECIPROCATORY MOTION Filed Nov. 27, 1944 3 Sheets-Sheet 1 ill =EI==== Inventor Faber! fCoO/e r072,

March 15, 1949. R, 'J, COCHRAN 2,464,214

MECHANICAL MOVEMENT FOR CONVERTING ROTARY INTO RECIPROCATORY MOTION Flled Nov 27 1944 5 SheetsSheet 2 PoZerz fCockran.

and

March 15, 1949. R J COCHRAN 2,464,214

MECHANICAL MOVEMENT FOR CONVERTING ROTARY INTO RECIPROCATORY MOTION Filed Nov. 27, 1944 3 Sheets-Sheet 3 wslllllllllmf Inventor Pderl f Coerara,

By fizmaofizm WWW Patented Mar. 15, 1949 MECHANICAL MOVEMENT FOR CONVERT- ING ROTARY INTO RECIPROCATORY MO- TION Robert J. Cochran, Woodward, kla., assignor to R. J. Cochran Power Unit, 1110., a corporation of Delaware Application November 27, 1944, Serial No. 565,323

6 Claims. 1

The present invention relates to improvements in mechanical movements or motions and has reference to a novel and improved structural adaptation and assemblage of parts wherein the rotary motion from a prime mover, such as an electric motor, is converted by a train of gears and a so-called planetary movement into reciprocatory motion for a rectilinear rod, such, for example, as that used as a plunger in a pump.

In order to permit the nature of the invention to be best understood, I have chosen an illustration thereof, that is, in the drawings, in which the assemblage is employed in connection with a conventional pump, the structural parts being so fashioned as to adapt said structure to the pump casing to serve as a closing and rod-operating head therefor.

In carrying out the principles of the invention, I have evolved and produced a special selection and mechanical coordination of parts all of which contribute their proportionate shares through the production of an arrangement which is calculated to insure longer service, dependable operation, provides for accessibility of parts for assembling and repairing, is exceptionally quiet in operation, and requires low-power consumption as compared with other makes and types.

Another phase of the construction has to do with the adoption and use of a structure which lends itself admirably well to constant efliciency, affords ways and means for satisfactory lubrication of parts, and otherwise aptly fulfills the essential requirements of a pump or equivalent compact power-developing and transmitting unit.

Due to the consolidation and simplification of mechanical elements employed in the overall construction of the unit, where it is employed as a pump head, it is possible to eliminate crossheads, lever arms, walking beams, connecting rods, and other complicating devices.

Furthermore, the essential characteristics or parts of the overall assemblage are suitably and appropriately encased to effectively house and protect the working parts and mechanisms.

More particularly, and bearing in mind the necessity of eliminating side thrusts in the movement of the reciprocatory pump rod and at the same time minimizing resulting wear of parts, I have perfected a novel power transmission gear arrangement in which a pinion, driven by pulleys or the like from a motor, serves to operate a pair of parallel, oppositely rotating gears, said gears, in turn, serving to control and actuate the aforementioned planetary motion, the latter having its main part movable through an orbital path and its auxiliary or complemental part traveling through said path but rotating on its own axis, the latter part being in the form of a crank and having a suitably swivelled connection, by a coupling, with the plunger rod so that it is moved up and down in a fixed vertical line.

Other features and advantages will become more readily apparent from the following description and the accompanying illustrative drawings.

In the drawings, wherein like numerals are employed to designate like parts throughout the views Figure 1 is a side elevational view showing a conventional pump structure with its plunger rod projecting above the upper end, the improved power unit, constituting the motion transmitting and converting means, being mounted on the pump casing.

Figure 2 is a view at right angles to Figure 1, that is, a viewobserving Figure 1 in a direction from right to left.

Figure 3 is a fragmentary side elevational view based on Figure 1 and showing the planetary type mechanical motion with its main and auxiliary parts shifted from the position in which they are aligned with each other and with the pump rod to positions substantially at right angles to each other and in diverging relation to the pump rod, this being one phase of the principle of operation.

Figure 4 is a horizontal section on the plane of the line 4-4 of Figure 2.

Figure 5 is a central horizontal section through the gearing assemblage orgear train and its associated connection with the twin part mechanical movement.

Figure 6 is a vertical central section through the main gear box or housing seen in Figure 5.

Figure 7 is a central sectional view through the novel mechanical movement.

Figure 8 is a section taken approximately on the plane of the line 8--8 of Figure 7.

It is to be repeated at this point that the power unit which constitutes the subject matter of this invenion is not, in any sense of the word, restricted for use in connection with pumps. It may be applied wherever an equivalent structure or device is satisfactorily usable. However, it is thought that the construction and principle of operation can be best understood by considering the invention in connection with a pump. Attention is, therefore, directed to Figure 1 in which the pumlx as a unitary structure, is denoted by the numeral l0. At the top of this is what may be called a base or stand II which embodies the lower half-section l2 of the gear housing or casing 3, which section i2 is provided with depending spaced parallel legs I4 connected to a base plate i5, which We will call an adapter, this being bolted to the casing of the pump. It is so arranged as to accommodate the reciprocatory plunger rod i6 whose upper end I? is rectangular in crosssection.

The gear casing is provided with an appro priate formation as at l8 (see Figure 6) to ac-' commodate bearings Is for a shaft 29, this provided on its outer end with a pulley 2| the shaft being provided, on its inner end, with a beveled pinion 22. The pulley 2| is driven by a suitable belt 23 which is trained over a pulley 24 on the shaft of the motor 25, the latter being supported above the gear casing and preferably bolted thereto, as shown in Figure 1. This provides a' unique casing, stand, motor and pulley assembly arrangement. However, the more important phases are to be hereinafter described.

In keeping with the foregoing, attention is directed to Figure 5, wherein it will be seen that a beveled gear 26 is in mesh with the pinion, this gear having a hollow axle 2! mounted for rotation in a bearing 23. This hollow axle 21 is keyed, as at 29, to a hub-like extension 30 on the main or master element 3| of the mechanical movement, but before going into detail as re-' gards the latter, attention is now directed to the companion beveled gear 32 which is also in mesh with the pinion 22, this gear having a subshaft 33 journaled in a bearing 33a in the casing structure. The stepped or shouldered shaft on the opposite side of the gear is rotatable in a bearing 34 carried by the beveled gear 26, a portion 35 being, journaled in the hollow axle 21 of the first-named gear. The reduced outer end 36 projects into the element 3|. is provided with suitable ball races for smoothness of operation, as is brought out in Figure 5.

The mechanical movement specifically now under consideration is made up of the aforementioned main element or part 3| and the auxiliary component part 3|a. These parts are actually in the form of cranks; therefore, when adjoined, provide a short ofqdouble crank motion,

the cranks operating,- obviously, in opposite directions. The part 3| is of general ovate form or configuration and comprises a casing made up of sections 3! bolted together. The outer end of the shaft 36 projects into this casing and is provided, as shown in Figure 7, with a suitably geared sprocket wheel 38 which is here shown accommodating a sprocket chain 39. The sprocket chain extends to the other end of the casing 31 where it is trained over a second sprocket wheel 40 on a sub-shaft 4| journaled in appropriate bearings, the sub-shaft 4| carrying a crank arm 42 and the crank arm being provided at its outer free end with a bearing to provide a pinned journal connection for an adapter collar 43 which fitson the plunger rod section This is secured in place by a set screw, as shown.

It is evident that the ovate casing, which is mechanically in the form of a crank, as it were, is keyed to the beveled gear 26. It is therefore turned with'sai-d gear under the influence of the motor driven pinion 22. Its outer end sweeps through an orbital path so that this part becomes the master motion transmitting and converting member; It also serves as a mount and carrier for the second crank 3|, which latter crank is This element '1 driven by the beveled gear 32. The beveled gear is also driven by the pinion and the two gears 26 and 32 operate in opposite rotation or directions, as is evident. Consequently, the shafts 35 and 36 drive the sprockets, and the sprockets drive the sprocket chains, thus transmitting the opposite reverse motion to the stub-shaft 4| and the crank arm 42 mounted thereon. It follows that this sub-shaft 4|, which is eccentric to the main hub pivot, travels through the aforementioned orbital path, but turns on its own axis. This provides the aforementioned planetary movement. The crank 42 goes in one direction and the main crank or part 3| rotates in the opposite direction. It follows that I have evolved and produced a simple, compact and reliable structure taking motion from the motor, transmitting it through the belt and pulley arrangement, then through the pinion and the gears 32 and 26. These two gears operating in opposite directions actuate the novel mechanical movement, and the latter, through its connection or collar 43, serves to move the plunger rod up and down in a true perpendicular manner, re lieving it of stress and strain and at the same time equalizing the push-pull motion. Obviously, by properly timing and coordinating all of the parts throughout the complete assemblage, a smooth motion-transmitting action and conversion from rotary to reciprocatory motion is had.

It is thought that persons skilled in the art towhich the invention'relates will'be able to obtain a clearunderstanding of the invention after considering the description inconnection with the drawings. Therefore, a more lengthy description is regarded as unnecessary.

Minor changes in the shape, size and arangement of details coming within the field of iii-'- vention claimed may be'resorte'd to in actual practice, if desired.

I clairni 1. A mechanical movement of the class described for reciprocating a plunger rod compris ing a hollow casing provided at one end and on one side with a hub-like extension, said extension being adapted for connection with a source of power for bodily revolving the casing so that the opposite outer end swings through an orbital path, a motion-transmitting shaft projecting into said casing and provided with a sprocket wheeha sub-shaft mounted in a bearing in the opposite outer end of the casing and provided with a sprocket wheel located in the casing, 21'; sprocket chain trained over said sprocket wheels, a crank arm on the stub-shaft, and means on said crank arm for operatively connecting same with the plunger rod.

2'. In a structural assemblage of the class described, motion-transmitting gearing, a casing enclosing same, a prime mover, an operating connection between the prime mover and gearing,- said casing being provided with a bearing, a main crank in the form of a hollowcasing having a hub-like extension for rotation in the bearing in said casing, an operating connection between said extension and the gearing in said casing, said hollow crank having a stub-shaft mounted ,in

hollow shank, whereby both cranks are revolved simultaneously through an orbital path, the second-named crank turning on its own axis while revolving through said orbit and turning in a direction opposite to that of the first crank.

3. In a structural assemblage of the class described for reciprocating a plunger rod, casing provided with bearings, a shaft mounted for rotation in said bearings, a pulley on the outer end of said shaft, a pinion on the inner end of said shaft, a pair of beveled gears mounted in parallelism in said casing, said pinion being simultaneously en aged with said beveled gear, one of said beveled gears having a hollow axle, the other beveled gear having an axle extending through the hollow axle and beyond same, a second casing mounted on the exterior of the first-named casing and provided with a journal mounted for rotation in a bearing in said first-named casing, said hollow axle being keyed to said journal, the axle on the second-named beveled gear extending into said second casing, the latter being provided with a bearing, a stub-shaft mounted in said bearing, an operating connection between the stub-shaft and a portion of said axle which extends into said second casing, a crank shaft mounted on said stub-shaft, and means connecting the crank shaft with the plunger rod.

4. A mechanical movement of the class described comprising a main crank arm having a hub-like extension adapted for connection with a source of power for bodily revolving the arm so that one end thereof swings through an orbital path, a motion transmitting shaft projecting through said arm and provided with a sprocket wheel, a stub shaft rotatably mounted in the crank in spaced relation to the hub-like extension and provided with a sprocket wheel in alignment with the first named sprocket wheel, a second crank on the stub shaft, and a chain trained over said sprocket wheels and operated by the aforementioned source of power and having connection with said main crank whereby both cranks are revolved simultaneously through an orbital path, the second named crank on its own axis while revolving through said orbit and turning in a direction opposite to that of the first crank.

5. A mechanical movement of the class described comprising a crank arm provided at one end and at one side with a hub-like extension, said extension being adapted for connection with a, source of power for bodily revolving the arm so that the opposite outer end swings through an orbital path, a motion-transmitting shaft projecting through said arm and provided with a sprocket wheel, a stub shaft mounted in a hearing in the opposite outer end of the arm and provided with a sprocket wheel located in alignment with the first named sprocket wheel, a

5 Number sprocket chain trained over said sprocket wheels, a crank arm on the stub shaft, and means on said second named crank arm for operatively connecting same with a device to be reciprocated.

6. In a structural assemblage of the class described, a casing provided with bearings, a shaft mounted for rotation in said bearings, a pulley on the outer end of said shaft, a beveled pinion on the inner end of said shaft, a pair of beveled gears mounted in parallelism in said casing, said pinion being simultaneously engaged with said beveled gear, one of said beveled gears having a hollow axle, the other beveled gear having an axle extending through the hollow axle and beyond same, a second hollow casing mounted on the exterior of the first named and provided with a hub-like extension mounted for rotation in a bearing in said first named casing, said hollow axle being keyed to said extension for bodily revolving the second hollow casing so the end opposite the extension swings in an orbital path, the axle on the second beveled gear extending into the second hollow casing and provided with a sprocket wheel, a stub shaft mounted in a bearing in the opposite outer end of the second hollow casing and provided with a sprocket wheel located in said second hollow casing, a sprocket chain trained over said sprocket wheels, a crank arm on the stub shaft, and means on said crank arm for operatively connecting same with a plunger rod, whereby the second hollow casing and the crank arm are revolved simultaneously, the crank arm turning on its own axis while revolving in an orbit with the second hollow casing and turning in a direction opposite to that of said second hollow casing for reciprocating said plunger rod.

ROBERT J. COCHRAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Borthwick Aug. 10, 1880 Woodward Oct. 3, 1899 Zook Nov. 24, 1908 Zook Mar. 30. 1909 Warner Oct. 13, 1925 Martois May 14, 1929 Perez Feb. 14, 1933 Bruin June 1, 1937 FOREIGN PATENTS Country Date Germany Dec. 3, 1919 Number 

